Stormier Paradise: More Hurricanes Predicted for Hawaii

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Scientists have suggested climate change may mean fewer tropical
cyclones in coming years, but a closer look at how global warming
affects regional weather patterns reveals Hawaiians should expect
more hurricane-force gales.

Tropical cyclones include hurricanes and typhoons, storms
that form in the world's tropical latitudes and spin ferociously
around a center called an eye. Only eight named tropical cyclones
hit Hawaii between 1979 and 2010, said scientists at the
University of Hawaii's International Pacific Research Center. But
the researchers' new model predicts a two-to-three-fold increase
in such storms between 2075 and 2099. The study is detailed in
the May 5 issue of the journal Nature Climate Change.

The results illustrate how global warming can lead to strong
regional climate differences, the researchers said. "Computer
models run with global warming scenarios generally project a
decrease in tropical cyclones worldwide. This, though, may not be
what will happen with local communities," lead study author
Hiroyuki Murakami said in a statement.

In the Pacific Ocean, tropical cyclones that could threaten
Hawaii
typically arise off the west coast of Mexico from June through
November. But lack of moisture over the Pacific and strong
westerly winds usually stop the storms from reaching the islands.

But the new model predicts that these westerly winds — called a
subtropical
jet and similar to the polar jet stream — will shift
northward in the next 60 years, removing the roadblock. The
projections also suggest the eastern Pacific Ocean will warm,
giving storms more fuel in the form of rising moisture.

"The yearly number we project, however, still remains very low,"
study co-author Bin Wang said in a statement. Between 1979 and
2003, on average, one tropical cyclone pummeled the islands every
four years. The researchers expect that number will double or
triple.

The storm projections are based on a
global climate model that includes the history of North
Pacific tropical cyclones and a temperature rise of 3.6 degrees
Fahrenheit (2 degrees Celsius).